the one and the, as arbitrary, limitations of the other.
Nor is the value of the doctrine of Evolution to the philosophic thinker
diminished by the fact that it applies the same method to the living and
the not-living world; and embraces, in one stupendous analogy, the
growth of a solar system from molecular chaos, the shaping of the earth
from the nebulous cubhood of its youth, through innumerable changes and
immeasurable ages, to its present form; and the development of a living
being from the shapeless mass of protoplasm we term a germ.

I do not know whether Evolutionism can claim that amount of currency
which would entitle it to be called British popular geology; but, more
or less vaguely, it is assuredly present in the minds of most
geologists.

Such being the three phases of geological speculation, we are now in a
position to inquire which of these it is that Sir William Thomson calls
upon us to reform in the passages which I have cited.

It is obviously Uniformitarianism which the distinguished physicist
takes to be the representative of geological speculation in general. And
thus a first issue is raised, inasmuch as many persons (and those not
the least thoughtful among the younger geologists) do not accept strict
Uniformitarianism as the final form of geological speculation. We should
say, if Hutton and Playfair declare the course of the world to have been
always the same, point out the fallacy by all means; but, in so doing,
do not imagine that you are proving modern geology to be in opposition
to natural philosophy. I do not suppose that, at the present day, any
geologist would be found to maintain absolute Uniformitarianism, to deny
that the rapidity of the rotation of the earth _may_ be diminishing,
that the sun _may_ be waxing dim, or that the earth itself _may_ be
cooling. Most of us, I suspect, are Gallios, "who care for none of these
things," being of opinion that, true or fictitious, they have made no
practical difference to the earth, during the period of which, a record
is preserved in stratified deposits.

The accusation that we have been running counter to the _principles_ of
natural philosophy, therefore, is devoid of foundation. The only
question which can arise is whether we have, or have not, been tacitly
making assumptions which are in opposition to certain conclusions which
may be drawn from those principles. And this question subdivides itself
into two:--the first, are we really contr